The first part of the address is called a protocol identifier and it indicates what protocol to use, and the second part is called a resource name and it specifies the IP address or the domain name where the resource is located. The protocol identifier and the resource name are separated by a colon and two forward slashes.

For example, the two URLs below point to two different files at the domain pcwebopedia.com. The first specifies an executable file that should be fetched using the FTP protocol; the second specifies a Web page that should be fetched using the HTTP protocol:

See "Countries and Their Domain Extensions" in the Quick Reference section of Webopedia.
See also "How Web Servers Work" in the "Did You Know...?" section of Webopedia.
Also see "Web Server Error Messages" in the Quick Reference section of Webopedia.

Document addressing - uniform resource term information
This World Wide Web Consortium page provides information on the uniform resource family of terms that deal with addressing documents on the Web. There is information on Uniform Resource Identifier (URI), Uniform Resource Locators (URL), Uniform Resource Names (URN), Uniform Resource Citations (URC), and how they all work together.

Internet Standards document on URLs
This Internet standards document specifies a Uniform Resource Locator (URL), the syntax and semantics of formalized information for location and access of resources via the Internet.

Web Search Engines & Directories
The following Quick Reference provides an overview of some of the more popular public Web Search Engines and Directories, including details on their history, information on how they work and tips for using each.

Webopedia Quick Reference: Countries and Their Domain Extensions
Ever see a Web address that doesn't end in .com, .org, or .edu? Most likely, the Web site is hosted on a server in another country, or, the origin of business is in another country. Here is a list of different country domain extensions and their corresponding countries sorted alphabetically according to the file extension.

Webopedia's "Did You Know...?" Section
Use this Webopedia knowledge section for an in-depth overview of specific technologies and occurrences in the areas of Computer Science, The Internet, and Computer Hardware and Software.

Webopedia's "Did You Know...All About Web Site Hosting"
So the time has come to finally get on the World Wide Web with a Web site of your own. Once the Web site and pages have been created, however, the question of where to put it still remains.

Webopedia's Did You Know... All About Web Browsers
The World Wide Web is a system of Internet servers that support specially formatted documents. AWeb browsers are used to make it easy to access the World Wide Web.

Webopedia's Quick Reference Section
Use this Webopedia reference section for information on common Internet and computer facts and occurrences.